1. Field of the Invention
The present invention relates to medical diagnostic equipment, and more particularly to medical diagnostic equipment related to the measurement and interpretation of blood pressures.
2. Description of the Related Art
The effects of high blood pressure continues to be a serious health problem. In the early 1990's, it was reported that two-thirds of Americans die with atherosclerotic blood vessels and that one-half of all Americans die as a result of these lesions.
There are many possible causes of high blood pressure each relating to different physiological mechanisms. In response, different hypertensive pharmaceuticals have been developed, each targeting one or more of the potential mechanisms. Examples are calcium channel blockers, angiotensin-converting enzyme inhibitors, beta-blocking drugs and their hybrids, diuretics, centrally-acting alpha2 agonists, alpha1-blocking agents, vasodilators, and adrenergic-blocking agents. Some of these medications act primarily on the microvascular (peripheral) resistance to blood flow, others on the lowered distensibility of larger arteries, cardiac output, or on various combinations of these.
Medical doctors and other practitioners routinely determine systolic and diastolic blood pressures using an inflatable cuff and sphygmomanometer and measure heart rate by manual timing of the pulse. Possible disease states are inferred from these values and this may lead to the use of additional diagnostic tests. The additional tests, such as measurement of cardiac output, for example, are often more invasive, time-consuming, and expensive. For these reasons, practitioners may prescribe medicines without performing them. This less-than-optimal therapy increases the likelihood of adverse side effects and when more than one agent is involved, increases the potential for undesirable drug interaction.
Clearly, in deciding on which type of hypertensive medication to prescribe for a particular patient, it is desirable to identify the underlying causes so that an informed decision, based on an accurate and timely diagnosis, can be made.